Better docstrings for content.update

[nealrichardson]

They're all pretty tautological, just restating the field name.

            name (str): The name of the content.
            title (Optional[str]): The title of the content.
            description (str): The description of the content.
            access_type (str): The access type of the content.
...

There's more useful information in the API docs, explaining what things are for, what valid values are, etc. We should grab those from the swagger spec and put them in there, translating to python as appropriate.

Probably also would be good to include xrefs to the hosted connect API docs for the relevant APIs.

[tdstein]

I've been going back and forth on whether to link directly to the API documentation. It's possible for the hosted documentation to diverge from the docstrings over time.

[tdstein]

Related to #135

[nealrichardson]

I've been going back and forth on whether to link directly to the API documentation. It's possible for the hosted documentation to diverge from the docstrings over time.

Possible but infrequent. We can also watch for changes in the API docstrings and make sure to copy them over. IMO the benefits of putting more detail in the SDK docs outweigh the cost of making sure they're accurate over time. I would be happy if no one other than us read the Connect API docs and they just read the SDK docs.